i) Field of the Invention
The present invention relates to an information storage apparatus for performing at least information reproduction via a carriage moving along a predetermined information storage medium with respect to the information storage medium, and the carriage.
ii) Description of Related Art
As an information storage apparatus for holding an information storage medium inside, and performing information recording or information reproduction with respect to the information storage medium, a hard disk drive, a CD drive, a magnetic optical disk drive, and the like have heretofore been known. Such information storage apparatuses are utilized as an external storage apparatus of a computer, and the like in a broad field.
The information storage apparatus is provided with read/write means for writing information into a desired position of the information storage medium, or reading the information from the desired position of the information storage medium. The read/write means is referred to as a magnetic head in a magnetic disk drive represented by a hard disk drive, and as an optical pickup in an optical disk drive represented by a CD drive.
In the conventional magnetic disk drive, a slider for contacting or approaching the surface of the information storage medium is attached to a tip end of an arm rotating in a parallel plane with respect to the information storage medium surface, and the magnetic head is generally mounted on the slider.
Moreover, in the conventional optical disk drive, the optical pickup is divided into a fixed portion provided with a laser diode and a photodetector and a movable portion (carriage) moving on a rail extending along the information storage medium surface, and a lens for focusing a laser light onto the information storage medium surface, and the like are generally mounted on the carriage.
In recent years, with rapid development of a computer, and with an increasing demand for handling of large data such as an image, rapid enhancement of information storage density has been demanded, and accordingly precision enhancement of a recording reproduction position has also been demanded. Moreover, as read/write means for satisfying both the enhancement of storage density and the enhancement of position precision, there is proposed read/write means constituted by attaching the slider to the carriage via a leaf spring or the like, and mounting the magnetic head or the lens on the slider.
Additionally, in the information storage apparatus, in order to enable high-speed access, in general, a disk information storage medium is used, the information storage medium is rotated by a motor at a high speed, and an air flow is generated in the vicinity of the information storage medium surface. Moreover, since a force received by the slider by the air flow is large enough to exceed own weight of the entire carriage, it is expected to be difficult to smoothly move the carriage along the rail simply by using the carriage used in the conventional optical disk drive. Therefore, there is a high possibility that the carriage position precision, that is, the recording reproduction position precision becomes insufficient.
The present invention has been developed in consideration of the aforementioned situations, and an object thereof is to provide an information storage apparatus which has a high precision of a recording reproduction position, and a carriage which realizes the information storage apparatus. When the information storage apparatus high in the precision of the recording reproduction position is realized, this largely contributes to rapid enhancement of a recording density of the information storage apparatus.
To achieve the aforementioned object, according to the present invention, there is provided an information storage apparatus for performing at least information reproduction via a carriage moving along a predetermined information storage medium with respect to the information storage medium.
The information storage apparatus comprises a rail extending along the information storage medium.
The carriage comprises three or more support members for supporting the carriage with respect to the rail, and a slider for contacting or approaching the surface of the information storage medium, and both a gravity center of the carriage and an application point of a force received by the slider by contacting or approaching the surface of the information storage medium exist inside a polygon whose vertexes are formed by the respective support members as seen from the information storage medium.
According to the information storage apparatus of the present invention, since both the carriage gravity center and the application point of the force received by the slider exist inside the polygon, the carriage is always dynamically stable. Therefore, the carriage can smoothly move along the rail, and a sufficient recording reproduction position precision can be obtained.
Moreover, preferably the information storage apparatus of the present invention xe2x80x9cfurther comprises an actuator for driving the carriage along the rail, and
when a height is defined by a distance from the surface of the information storage medium, the height of a position obtained by weighting and averaging respective positions using a friction resisting force generated in the position of the support member contacting the rail as a weight, the height of the gravity center of the carriage, and the height of the application point of a driving force of the actuator applied to the carriage are the same heightxe2x80x9d.
In order to smoothly move the carriage along the rail at a high speed, it is desirable to devise the position in which the driving force for driving the carriage is applied to the carriage. According to the information storage apparatus provided with the actuator, since the driving force is applied to the application point, the carriage can smoothly be moved along the rail at the high speed. As a result, the information storage apparatus high in the recording reproduction position precision and fast in the recording reproduction speed is realized.
To achieve the aforementioned object, according to the present invention, there is provided a carriage comprising:
a slider for contacting or approaching a predetermined information storage medium surface; and
three or more support members for supporting the carriage,
Wherein both an application point of a force received by the slider by contacting or approaching the information storage medium surface, and a gravity center of the carriage exist inside a polygon whose vertexes are formed by the respective support members as seen from the information storage medium.